Various silk based drug delivery systems were designed to exploit silk's novel material properties in order to attain slow, sustained, controlled release. Using the small molecule model drug adenosine, release profiles from various silk delivery systems were characterized in vitro. The therapeutic potential of the implants was validated in a dose response study in the rat model of kindling epileptogenesis. Adenosine releasing silk implants engineered to release varied target release doses were implanted in rat brains and dose-dependent delays in epileptogenesis were observed over 14 days. We conclude that silk-based adenosine delivery systems represent a safe and efficient strategy to suppress seizures, and that these degradable, implantable biomaterials could potentially be applied to a range of therapeutics.